Electric inductional transformer



L .L t. 0u o0 h 1|. Q O0 1.. e l 8 h Lb S R G 2 E 0 m d 0 e UI .Tu S D vT N 6 Td A .fu R a Y m P u A N N W. M U D N W 1 G T.. DTR. 1J 1. 1 A\. M 6 0 4 M 0 O m N 4(No Model.) 2 Sheets-Sheet 2.

' W. STANLEY, Jr.

ELECTRIC INDUGTIONAL TRANSFORMBR. 110.461,135. Patented ont. 13, 1891.

UNITED STATES- -PATENT OFFICE.

IVILLIAM STANLEY, JR., OF PITTSFIELD, MASSACHUSETTS.

A ELECTRIC INDUCTIONAL TRANSFORMER.

SPECIFICATION forming part 0f Letters Patent No. 461,135, dated October 13, 1891.

i i Application tiled January 16, 1891- Serial No. 377,946. (No model.)

To till whom it may concern.-

Be it known that I, WILLIAM STANLEY, Jr., a citizen of the United States, and a resident of Pittsfield, in the county of Berkshire and State of Massachusetts, have invented certain new and useful. Improvements in Electric Inductional.'lransformers, ot' which the following is a specification.

My invention relates to certain improvements in the mechanicaland constructional details of that class of transformers usually employed in the distribution of electricity for illuminating and other like purposes. Such a transformer consists of primary and secondary coils of insulated copper Wire, usually separately wound and separately insulated from each other and also from the mass of iron,technieallytermed the coi-e, upon which their inductive action is exerted'. Experience has shown that a very efficient organization of such a transformer is obtained when the mass ot' iron constituting the core is formed of thin plates or laminas sufficiently insulated from each other to preventthe transmission fromplate to plate of induced currents of low electro-motive force, and also when the mass of iron formed by assembling or grouping a considerable number of these plates together is made to completely envelop and inclose the copper-wire coils on every side. I have found by experiment that the efficiencyof a transformer constructed in the general manner which I have described is considerably increased by permitting to the individual plates ofthe core an independent but restricted motion among themselves in response to the intermittent magnetic forces generated Within them bythe inliuence of alternating electriccurrents traversing the magnetizing coil.

The general object of my invention is to and economy of hand laborin the assemblage of the parts.

In the accompanying drawings, Figure l is a vertical transverse section of atransfprmer containing my improvements. Fig. 2 is a vertical longitudinal section of the same, and Fig. 3 is a perspective view, which exhibits more clearly the mannerin which the groups of plates are assembled together.

Referring to Figs. l and 2, P and S represent the primary and secondary coilsot` the converter. These are preferably wound in the form of a rectangle with semicircular ends, bearing a general resemblance in form to one link of a chain formed-of a'square bar of metal. The primary coil P (see'Fig. 1) 'is usually of Acomparatively thin Wire and is wound outside the secondary coil S, which is composed of thicker wire. Instead of-winding these coils upon a temporary form inthe manner heretofore usually practiced,I prefer to permanently wind them directly upon a mass or group of plates C, which ultimately constitutes the cent-ral section of the completed core. This group is formed of thin laminze resembling in outline the cross-section of a bobbin, as seen at C, in Fig. 1. Each plate consists of a rectangular portion C, occupying the space within the inner coil S and having integral extensions c c, of triangular outline, project'ing outside the mag' netizin g coil. The 'plates'of this central group, being insulated from each other to the extent required in any well-known or suitable manner, are secured together by bolts ff, having suitable clamping-nuts upon their ends, as shown in the drawings. The insulated-wire .coils having been thus wound ou the central portion C of the sectional core, two exterior groups of plates of similar thickness C and C2 are applied thereto in such a manner as .to complete a double magnetic circuit, surrounding both halves of the coils every side and leaving exposed only the scmicircular portion at the ends. These two sections or groups Cand Cgare composed of a sufficient number of thin plates of an arch or bridge shape, as seen in Figs. l and 3, the abntments of the arch or bridge being cut. 01T or formed obliquely, as shown at c c', so as to bear against the corresponding inclined or oblique edges ot' the central core at c c. At the middle of eacharch or bridge is a saddle d, of

'insulating material, which transmits to the entire group or assemblage, of plates the' pressure of the arch-shaped clamps B B, one of which spans or incloses each of the exterior groupsof plates. The two arch-shaped Aclamps are held together by the longitudi nally-adjustable bolts and nuts b b. Y

From the description hereinbefore given it will be understood that when the groups of plates are assembled together and the archshaped clamps B IB put in placeand properly secured by screwing up the-bolts b b the entire pressure of the clamping devices will bev exerted upon the centers of the arch-shaped plates through the saddles d d, and that this pressure will be exerted not upon the group as a unit, but separately upon each individual 1 plate of the group, which will be therefore free to adjust 'itselfvin such manner as to endure the iirmest possible contact'of its inclined edges c cbagainpst the corresponding opposite plate of the central core C, and, furthermore,

it wvill be obvious that, being supported in positions inthe completed transformer, the

this manner at three points. only upon the edges, each plate will yield to a limited but suiicient extent under the stress of the magnetic forces due to the action of the magnetizing coil when excited by an alternating current. The position of the three groups of plates with reference to each other will perhapsbe best understood by an inspection of Fig.- 3,.which exhibits them in their relative coil and the external clampingdevices being omitted. After the parts are assembled together. and properly clamped the apparatus may be placed Within 'an inclosing metallic cylindrical shell or caseE, havin g, preferably,

'a' lining of insulating material. The termilooselyk in their supports, so aste be capable of mutually-independent self-adjustment in planes substantially parallel with their respectiv'e surfaces.

2. In an electric transformer, a group of detached arch or bridge shaped plates bear-` ingagainst abutments composed of Vintegral plates ygrouped in like manner, said plates or groups of plates being held loosely in their supports, so as to be capable of mutually-independent self-adjustment when maintained in position by pressure exerted against the edges of the plates of which said group is formed.

3. A transformer-plate in the form ofan arch or bridge spanning the magnetizing-coil,A having oblique bearings at each end, and fitted with a saddle ,forming a third bearing at the center of the bridge.

4. ln an electrical transformer, a core inclosing a magnetizing-coil and consisting of` three sets or groups of plates, One set Occupying the space between the opposite sides of the coil and inclosiug said coil on three of its sides and the other two groups covering the remaining portions of the coil and completing the magnetic circuit, in combination with clamping devices for maintaining forcible contact-between said groups of plates.

" 5. A sectional transformer-plate consisting of a rectangular central section inclosed within the magnetizing-coil and projecting therefromron each side, in combination with .two bridge-shapedsections spanning and inclosing the coil, and arch or bridgeshaped clamps bearing against the exterior of the bridge-shaped sections at a 'central' point and having their abutments united by longitudinallyadj ustable clamps.

In testimony whereof I have hereunto subscribed my name this 14th day of January,

. WILLIAM STANLEY, JR.

Witnesses: FRANKLIN LEONARD POPE, CAROLINE E. DAVIDSON, 

